Induction-motor.



R. E. HELLMUND.

INDUCTION MOTOR.

APPLICATION FILED JUNE 28. 1911.

Patented Nov. 2, 191.

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R. E. HELLMUND.

mnucnou MOTOR.

Patented Nov. 2, 1915.

APPLICATION FILED JUNE 28,191].

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\ IIIIIIIIIIFIHHEIW Q I I I WlTNESSES: glNvENTOR S 5 Z ATTORNEY UNITEDSTATES PATENT OFFICE.

BUDOLF E. HELLMUND, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC AND MANUFAUIURING COMPANY, A CORPORATION OF PENN-SYLVANIA.

INDUCTION-MOTOR.

Application filed June 28, 1311.

a resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement inInduction-Motors, of which the following I is a specification.

My invention relates to dynamo-electric machines and it has specialreference to the core structures and the ventilation of asynchronousmotors.

One object of my invention is to provide a core structure having a. fluxpath of substantially uniform reluctance and composed of square ornearly square laminae.

Another object of my invention is to provide a stator particularlyadapted for induction motors and consisting of end members which aresubstituted for the usual frame of the machine and means for blowing airacross the exposed surface of the core member.

Induction motors and other dynamo-electric machines, as heretoforeusually con terially simplify the structure by omitting the stationarycylindrical frame entirely and substitute therefor a pair of end ringswhich are secured to the structure by the same bolts or rivets that holdthe laminae together, The laminae of which the core member itself iscomposed are stamped from relatively small square plates, only thecorners of the laminae being rounded. The laminae are assembled ingroups, which are staggered relative to each other, in order to equalizethe sectional area of the core member.

Figure 1 of the accompanying drawings is a partially sectional elevationof a motor constructed in accordance with my invention; Fig. 2 1S an endview of the motor 0 shown In Fig. 1., with certain or the parts brokenaway to disclose the arrangement of core plates, and Figs. 3, l and 5are views, on a relatively small scale, 1llustrat mg the arrangement ofthe groups of Specification of Letters Patent.

Patented Nov. 2, 1915.

Serial No. 635,993.

laminae in the core member of the motor shown in the other figures.

Referring to the drawings, the motor here shown comprises a laminatedcore member 1, a pair of end rings 2 and 3, end brackets i and 5 and abase or supporting structure 6.

The core structure 1 is built up of a large number of punched plates orlaminae 7 having the form shown in Fig. 3, and arranged in groups 8, asshown in Fig. 1, which are staggered or skewed, as shown in Fig. 2. Eachcore plate is provided with a central opening which determines the boreof the machine, adjacent to which slots 9 are out to produce the usualcore teeth 10. Each of the core plates is substantially square inoutline, the corners being rounded, however, in order to reduce the costof the motor and the amount of scrap material resulting from themanufacture of the core members.

Although there are a number of groups of punchings, there are oniy threedifferent group arrangements which are respectively illustrated in Figs.3, a and 5 of the drawings. By utilizing the staggered arrangement ofgroups, as shown, the sectional area and the magnetic reluctance aresubstantially the same at all points in the magnetic circuit.

Holes 11 are provided in the corners of the plates to receive bolts orrivets 12 which hold the plates together and clamp them to the end rings2 and 3.

The end rings 2 and 3, which are of slightly larger diameter than thecore structure, are of substantially L-shape in cross section and areprovided with holes 13 through which a circulation of air may be set upacross the outer surface of the core member by the use of fan blades(not shown) or other suitable means carried by the rotating part of themachine in a well known manner.

The base or supporting member 6 is riveted, or otherwise secured to therings 2 and 3 and is preferably stamped out of relatively heavy sheetmetal.

The end brackets 4 and 5 may be of any suitable form and are secured tothe rings 2 and 3 by means of bolts 14.

The skewed arrangement of core groups provides a very large externalradiating surface and, since the core member is not surrounded by any ofthe usual frame struc tures, it is evident that the temperature of themotor will be relatively low under normal operating conditions.

ldodifications in size and arrangement of parts may, of course, be madeWithin the spirit and scope of my invention.

1 claim as my in vcntion:

l. A stator for dynamo-electric machines comprising a plurality ofskewed or staggered polygonal plates, externally concave end ringshaving inwardly projecting flanges, means for clamping said platesbetween the flanges oi? said end rings, and a supporting base upon whichsaid end rings rest and to which they are clamped.

A stator for dynamo-electric machines comprising a pair of externallyconcave end rings having inwardly projectii'ig flanges, a plurality ofinterposed skewed or staggered polygonal plates of magnetizablematerial, means for clamping the corners ofsaid plates between said endring flanges, and a supporting base upon which said end rings rest andto which they are clamped.

3. A stator for dynamo-electric machines comprising pair of end ringsand a plurality o1 'roups of square plates having rounded corners, saidgroups being skewed or staggered relative to each other.

e. A stator for dynamo-electric machines comprising a plurality ofgroups of square plates having rounded corners, said groups Copies ofthis patent may be obtained for five cents each,

being skewed or staggered relative to each other, a pair of externallyconcave end rings having inwardly projecting flanges and means forclamping the rounded corners of fjw said plates between the iianges ofsaid end rings.

A stator for dynamo-electric machines comprising a pair of externallyconcave end rings comprising imvardly projecting flanges,iiitei'pcsed'core laminae, and means for clamping the laminm between thering flanges, the flanges being provided with openings through which aircurrents may to the outer surfaces of the core laminae.

6. A stator for dynamo-electric machines comprising a pair of end ringshaving inwardly extending flanges at their adjacent cages and aplurality of skewed or staggered groups of square magnetizable plateshaving rounded corners. said ring iians being pro vided with spacedopenings through which air currents may pass to the outer surfaces ofthe assembled plates.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof June, 1911.

RUDOLF E. HELLMUND.

Witnesses:

R. E. FERRY,

B. B. HINEs.

addressing the Commissioner of Patents,

Washington, D. G.

